<!doctype html>
<html lang="en">
<head>
<title>:not() test</title>
<style>
div {
    background: yellow;
}

div:not(div div) {
    background: lime;
}
</style>
</head>
<body>
  <div>I am not a descendant and should be green.</div>
  <div>
    <div>I am a descendant and should be yellow.</div>
  </div>
</body>
</html>
